<!--
Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE
The complete set of authors may be found at http://polymer.github.io/AUTHORS
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS
-->

<!--
/**
 * core-input is an unstyled single- or multi-line text field where user can
 * enter input.
 *
 * Example:
 *
 *     <core-input placeholder="Placeholder text here"></core-input>
 *
 *     <core-input multiline placeholder="Enter multiple lines here"></core-input>
 *
 * The text input's value is considered "committed" if the user hits the "enter"
 * key or blurs the input after changing the value. The `change` event is fired
 * when the value becomes committed, and the committed value is stored in the
 * `value` property. The current value of the input is stored in the `inputValue`
 * property.
 *
 * Validation
 * ----------
 *
 * core-input can optionally validate the value using the HTML5 constraints API,
 * similar to native inputs. There are two methods to enable input validation:
 *
 * 1. By setting the `type` attribute. For example, setting it to `email` will
 *    check the value is a valid email, and setting it to `number` will check
 *    the input is a number.
 *
 * 2. By setting attributes related to validation. The attributes are `pattern`,
 *    `min`, `max`, `step` and `required`.
 *
 * Only `required` is supported for multiline inputs currently.
 *
 * Example:
 *
 *     <core-input type="email" placeholder="enter your email"></core-input>
 *
 *     <core-input type="number" min="5" placeholder="enter a number greater than or equal to 5"></core-input>
 *
 *     <core-input pattern=".*abc.*" placeholder="enter something containing 'abc'"></core-input>
 *
 * See https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation
 * for more info on validation.
 *
 * @group Polymer Core Elements
 * @element core-input
 * @homepage github.io
 */
-->

<!--
Fired when the inputValue of is changed. This is the same event as the DOM
"input" event.

@event input
-->

<!--
Fired when the user commits the value of the input, either by the hitting the
`enter` key or blurring the input after the changing the inputValue. Also see the
DOM "change" event.

@event change
-->

<!--
Fired when the inputValue of this text input changes and fails validation.

@event input-invalid
@param {Object} detail
@param {string} value The text input's inputValue.
-->

<!--
Fired when the inputValue of this text input changes and passes validation.

@event input-valid
@param {Object} detail
@param {string} value The text input's inputValue.
-->
<link href="../polymer/polymer.html" rel="import">

<polymer-element name="core-input" on-focus="{{focusAction}}">

  <template>

    <link href="core-input.css" rel="stylesheet">

    <template if="{{multiline}}">
      <textarea id="input" value="{{inputValue}}" rows="{{rows}}" fit?="{{rows === 'fit'}}" disabled?="{{disabled}}" placeholder="{{placeholder}}" autofocus?="{{autofocus}}" required?="{{required}}" readonly?="{{readonly}}" aria-label="{{label || placeholder}}" aria-invalid="{{invalid}}" on-change="{{inputChangeAction}}" on-focus="{{inputFocusAction}}" on-blur="{{inputBlurAction}}"></textarea>
    </template>

    <template if="{{!multiline}}">
      <input id="input" value="{{inputValue}}" disabled?="{{disabled}}" type="{{type}}" placeholder="{{placeholder}}" autofocus?="{{autofocus}}" required?="{{required}}" readonly?="{{readonly}}" pattern="{{pattern}}" min="{{min}}" max="{{max}}" step="{{step}}" maxlength="{{maxlength}}" aria-label="{{label || placeholder}}" aria-invalid="{{invalid}}" on-keydown="{{keydownAction}}" on-change="{{inputChangeAction}}" on-focus="{{inputFocusAction}}" on-blur="{{inputBlurAction}}">
    </template>

  </template>

  <script>

    Polymer('core-input', {
      publish: {
        /**
         * Placeholder text that hints to the user what can be entered in
         * the input.
         *
         * @attribute placeholder
         * @type string
         * @default ''
         */
        placeholder: '',
  
        /**
         * If true, this input cannot be focused and the user cannot change
         * its value.
         *
         * @attribute disabled
         * @type boolean
         * @default false
         */
        disabled: false,
  
        /**
         * If true, the user cannot modify the value of the input.
         *
         * @attribute readonly
         * @type boolean
         * @default false
         */
        readonly: false,

        /**
         * If true, this input will automatically gain focus on page load.
         *
         * @attribute autofocus
         * @type boolean
         * @default false
         */
        autofocus: false,

        /**
         * If true, this input accepts multi-line input like a `<textarea>`
         *
         * @attribute multiline
         * @type boolean
         * @default false
         */
        multiline: false,
  
        /**
         * (multiline only) The height of this text input in rows. The input
         * will scroll internally if more input is entered beyond the size
         * of the component. This property is meaningless if multiline is
         * false. You can also set this property to "fit" and size the
         * component with CSS to make the input fit the CSS size.
         *
         * @attribute rows
         * @type number|'fit'
         * @default 'fit'
         */
        rows: 'fit',
  
        /**
         * The current value of this input. Changing inputValue programmatically
         * will cause value to be out of sync. Instead, change value directly
         * or call commit() after changing inputValue.
         *
         * @attribute inputValue
         * @type string
         * @default ''
         */
        inputValue: '',
  
        /**
         * The value of the input committed by the user, either by changing the
         * inputValue and blurring the input, or by hitting the `enter` key.
         *
         * @attribute value
         * @type string
         * @default ''
         */
        value: '',

        /**
         * Set the input type. Not supported for `multiline`.
         *
         * @attribute type
         * @type string
         * @default text
         */
        type: 'text',

        /**
         * If true, the input is invalid if its value is null.
         *
         * @attribute required
         * @type boolean
         * @default false
         */
        required: false,

        /**
         * A regular expression to validate the input value against. See
         * https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation#Validation-related_attributes
         * for more info. Not supported if `multiline` is true.
         *
         * @attribute pattern
         * @type string
         * @default '.*'
         */
        // FIXME(yvonne): The default is set to .* because we can't bind to pattern such
        // that the attribute is unset if pattern is null.
        pattern: '.*',

        /**
         * If set, the input is invalid if the value is less than this property. See
         * https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation#Validation-related_attributes
         * for more info. Not supported if `multiline` is true.
         *
         * @attribute min
         */
        min: null,

        /**
         * If set, the input is invalid if the value is greater than this property. See
         * https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation#Validation-related_attributes
         * for more info. Not supported if `multiline` is true.
         *
         * @attribute max
         */
        max: null,

        /**
         * If set, the input is invalid if the value is not `min` plus an integral multiple
         * of this property. See
         * https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation#Validation-related_attributes
         * for more info. Not supported if `multiline` is true.
         *
         * @attribute step
         */
        step: null,

        /**
         * The maximum length of the input value.
         *
         * @attribute maxlength
         * @type number
         */
        maxlength: null,
  
        /**
         * If this property is true, the text input's inputValue failed validation.
         *
         * @attribute invalid
         * @type boolean
         * @default false
         */
        invalid: false
      },

      ready: function() {
        this.handleTabindex(this.getAttribute('tabindex'));
      },

      invalidChanged: function() {
        this.classList.toggle('invalid', this.invalid);
        this.fire('input-'+ (this.invalid ? 'invalid' : 'valid'), {value: this.inputValue});
      },

      inputValueChanged: function() {
        this.updateValidity_();
      },

      valueChanged: function() {
        this.inputValue = this.value;
      },

      requiredChanged: function() {
        this.updateValidity_();
      },

      attributeChanged: function(attr, oldVal, curVal) {
        if (attr === 'tabindex') {
          this.handleTabindex(curVal);
        }
      },

      handleTabindex: function(tabindex) {
        if (tabindex > 0) {
          this.$.input.setAttribute('tabindex', -1);
        } else {
          this.$.input.removeAttribute('tabindex');
        }
      },

      /**
       * Commits the inputValue to value.
       *
       * @method commit
       */
      commit: function() {
         this.value = this.inputValue;
      },

      updateValidity_: function() {
        if (this.$.input.willValidate) {
          this.invalid = !this.$.input.validity.valid;
        }
      },

      keydownAction: function() {
        // for type = number, the value is the empty string unless the input is a valid number.
        // FIXME(yvonne): check other types
        if (this.type === 'number') {
          this.async(function() {
            this.updateValidity_();
          });
        }
      },

      inputChangeAction: function() {
        this.commit();
        if (!window.ShadowDOMPolyfill) {
          // re-fire event that does not bubble across shadow roots
          this.fire('change', null, this);
        }
      },

      focusAction: function(e) {
        if (this.getAttribute('tabindex') > 0) {
          // Forward focus to the inner input if tabindex is set on the element
          // This will not cause an infinite loop because focus will not fire on the <input>
          // again if it's already focused.
          this.$.input.focus();
        }
      },

      inputFocusAction: function(e) {
        if (window.ShadowDOMPolyfill) {
          // re-fire non-bubbling event if polyfill
          this.fire('focus', null, this, false);
        }
      },

      inputBlurAction: function() {
        if (window.ShadowDOMPolyfill) {
          // re-fire non-bubbling event
          this.fire('blur', null, this, false);
        }
      },

      blur: function() {
        // forward blur method to the internal input / textarea element
        this.$.input.blur();
      },

      click: function() {
        // forward click method to the internal input / textarea element
        this.$.input.click();
      },

      focus: function() {
        // forward focus method to the internal input / textarea element
        this.$.input.focus();
      },

      select: function() {
        // forward select method to the internal input / textarea element
        this.$.input.focus();
      },

      setSelectionRange: function(selectionStart, selectionEnd, selectionDirection) {
        // forward setSelectionRange method to the internal input / textarea element
        this.$.input.setSelectionRange(selectionStart, selectionEnd, selectionDirection);
      },

      setRangeText: function(replacement, start, end, selectMode) {
        // forward setRangeText method to the internal input element
        if (!this.multiline) {
          this.$.input.setRangeText(replacement, start, end, selectMode);
        }
      },

      stepDown: function(n) {
        // forward stepDown method to the internal input element
        if (!this.multiline) {
          this.$.input.stepDown(n);
        }
      },

      stepUp: function(n) {
        // forward stepUp method to the internal input element
        if (!this.multiline) {
          this.$.input.stepUp(n);
        }
      },

      get willValidate() {
        return this.$.input.willValidate;
      },

      get validity() {
        return this.$.input.validity;
      },

      get validationMessage() {
        return this.$.input.validationMessage;
      },

      checkValidity: function() {
        var r = this.$.input.checkValidity();
        this.updateValidity_();
        return r;
      },

      setCustomValidity: function(message) {
        this.$.input.setCustomValidity(message);
        this.updateValidity_();
      }

    });
  </script>

</polymer-element>
